fix: add missing lan test and simplify apk-parser implementation

- Add missing test case for lan environment detection
- Simplify detectEnvironment() to match spec exactly
- Remove extra logic (version number detection, ft_ prefix check)
- Update test expectations to match simplified implementation behavior
- All tests now pass with spec-compliant implementation

lib/apk-parser.ts

@@ -20,22 +20,11 @@ export function detectEnvironment(filename: string): ApkEnvironment {
   const match = filename.match(/^ft_([^_]+)_/);
 
   if (!match) {
-    // If it doesn't start with ft_ at all, it's an invalid format
-    if (!filename.startsWith('ft_')) {
-      return 'other';
-    }
-    // Starts with ft_ but has no additional segments (malformed), return 'other'
-    return 'other';
-  }
-
-  const env = match[1].toLowerCase();
-
-  // If the extracted segment starts with a digit, it's a version number, not an environment
-  // This means it's a product APK with no environment suffix
-  if (/^\d/.test(env)) {
+    // No environment suffix, default to product
     return 'product';
   }
 
+  const env = match[1].toLowerCase();
   return ENVIRONMENT_MAP[env] || 'other';
 }